Dr Avneet Kaur, B.H.M.S.
Introduction:
Macula: Oval, highly pigmented yellow spot near center of retina, has a diameter of around 5mm. Histologically, it contains 2 or more layers of ganglionic cells. Fovea lies in the center of the macula and contains the largest concentration of cone cells in the eye and is responsible for central vision.
Lipofuscin: Finely granular yellow brown pigment granules composed of lipid containing residues of lysosomal digestion. Lipofuscin accumulation is a major risk factor implicated in macular degeneration.
Definition:
It is an autosomal dominanat disorder, clinically presents in childhood, with appearance of a yellow or orange yolk like lesion in macula. It was named After a German ophthalmologist Dr. Franz Best.
It can be of 2 types; Early onset/Childhood onset and Adult onset. Usually affects both eyes, can be occasionally unilateral.
Pathology:
Mutation on chromosome number 11, on gene RDS and VMD2 causes this disease.
Lesions are restricted only to the eye and no systemic associations exist.
Dysfunction in bestrophin results in abnormal fluid and ion transport by the retinal pigment epithelium (RPE). Lipofuscin accumulates within the RPE cells and in sub-RPE space. RPE develops degenerative changes and secondary loss of photo-receptor cells results.
Morbidity:
Visual acuity is good in pre-vitelliform stage.
Even with egg yolk appearance vision remains 6/6 to 6/15 for many years
Visual acuity deteriorates in scrambled egg stage
RPE atrophy in a geographical pattern with possible development of choroidal neovascularization membrane is indicative of further deterioration.
History:
Initially asymptomatic, with fundus lesions noted on examination
Visual Symptoms- Decreased Acuity / blurring
Metamorphosia/ distorted vision, grid lines appear wavy
Symptoms worsen with progress of disease to atrophic stage.
Examination:
Stage-I/ Pre-vitelliform: Vision-6/6
Normal Macula or subtle RPE changes, EOG abnormal
Stage-II/Vitelliform: Vision-6/6 – 6/15
Well circumscribed, 0.5mm – 5 mm round, elevated, yellow/orange lesions –EGG YOLK appearance.
Stage-III/Pseudohypopyon: Vision-6/6 – 6/15
Lipofuscin accumulates in the sub retinal space in a cyst with fluid level formed
Stage-IV/Vitelliruptive: Vision-6/6 – 6/30
Breakup of uniform lesion, pigment clumping and early atrophic changes- SCRAMBLED EGG appearance.
Stage-V/Atrophic: Vision-<6/60
Lipofuscin disappears over time, leading to sub retinal fibrosis and choroidal neovascularization.
Management:
Increased intake of vegetables and fruits
Reduce or eliminate caffeine and carbonated drinks from diet
Avoid aspartame, mono-sodium glutamate, manmade fats and fat blockers which impair absorption of carotinoids.
Eliminate deep fried foods, reduce satured fat and cholesterol
Vitamin supplementation.
Therapeutics:
Ginko biloba: it contains flavinoids which may increase blood supply to the macula and aid in age related macular dystrophy. Improves blood circulation to the macula and the optic nerve.
Napthalinum: Marked affinity for the eye. It produces detachment of the retina; papillo-retinal infiltration; deposits in patches upon the retina; amblyopia and consecutive amaurosis; sparkling synchisis; soft cataract. Exudation in the retina, choroid and ciliary body. Cataract.
Bibliography:
Best Macular Dystrophy, Vitelliform Macular Dystrophy Type 2: Ian M MacDonald, MD, CM; Thomas Lee, MD, MSc University of Alberta
Bests Disease: Michael Altaweel, MD, FRCS(C), Associate Professor, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health
A new manual on material medica and homeopathic therapeutics-W.Boericke
Vitelliform Macular Dystrophy – A Bibliography and Dictionary for Physicians, Patients, and Genome Researchers
useful information..